Magento – Change Images shown in slider

Backtracing the code

1. Mage_Catalog_Model_Product::addImageToMediaGallery
2. Mage_Catalog_Model_Product_Attribute_Backend_Media::addImage
3. Varien_File_Uploader::getDispretionPath

It seems that the path is build here. Since you can't override a Varien file from a custom module you will have to copy the file to app/code/local/Varien/File/Uploader.php. There you can change the way the path is build.

However, this will not only affect products in that case. You might want to override Mage_Catalog_Model_Product_Attribute_Backend_Media::addImage from a custom module to limit the scope of the changes to just products. So instead of calling Mage_Core_Model_File_Uploader::getDispretionPath on line 286 you might want to change that line into calling a custom method for returning the path.

Add the code in your controller file

public function saveAction() 
{
    ...

    if (!empty( $_FILES['main_image']['name'] )) 
    {
        $data['main_image'] =  $_FILES['main_image']['name'] ;
    } 
    else 
    {
        if (isset($data['main_image']['delete']) && $data['main_image']['delete'] == 1) 
        {
            if ($data['main_image']['value'] != '')
                $this->removeFile($data['main_image']['value']);
            $data['main_image'] = '';
        }
        else 
        {
            unset($data['main_image']);
        }
    }

    ...
}
public function removeFile($file) 
{
        $_helper = Mage::helper('ram');
        $file = $_helper->updateDirSepereator($file);
        $directory = Mage::getBaseDir('media') . DS .'ram_images' ;
        $io = new Varien_Io_File();
        $result = $io->rmdir($directory, true);
}

Create below function in Helper Class

 public function updateDirSepereator($path) 
    {
        return str_replace('\\', DS, $path);
    }